Just as a more permissive attitude to cannabis gains momentum in the United States, so does a more restrictive attitude to tobacco. It is as if there were a law of the conservation of prohibition: if one substance is permitted after having been prohibited, another will be prohibited after having been permitted.

While Colorado permits the use of marijuana by those over 21 for any purpose, New York City prepares to prevent sales of tobacco to anyone under the age of 21. An article in a recent edition of the New England Journal of Medicine comes out strongly in favor of this more restrictive approach to the sale of tobacco. The arguments it uses and those it refutes are instructive.

Those who go on to smoke throughout their lives generally start at an early age: earlier, that is, than 21. Thus if adolescents could be discouraged from smoking, rates of smoking among adults would decline markedly.

Of course, it is not enough for something to be desired or desirable for it to be feasible. Such evidence as exists, however, suggests that restricting sales to minors might work. A town in Massachusetts, Needham, forbade the sale of tobacco to those under 21, and the rate of smoking among high school students declined by nearly half five years later. The rate in a neighboring town, which did not impose the ban, fell in the same time by only a third as much. Furthermore, raising the minimum drinking age to 21 was followed by (one cannot with absolute certainty say caused) a fall in alcohol consumption by adolescents, drunk driving, and motor accidents.

So long as the ban on sales to young people is not universal there remains the possibility that they will travel to another jurisdiction to obtain tobacco. But, argue the authors of the article (all from Harvard), such young people are not highly mobile and will not find it so easy to travel. They say, “Although those who are already addicted may be sufficiently motivated to [travel in search of tobacco], increasing the transaction costs associated with obtaining tobacco products may reduce daily consumption among regular users and discourage others from starting to smoke.”

They recognize that such a ban is a restriction of liberty which some citizens might find offensive. After all, 18 year olds are deemed mature enough to vote and to sign up for the military. But they meet this objection by saying that at 18 that “research suggests that adolescents can become dependent on nicotine very rapidly, at lower levels of consumption than adults; that they are undergoing alterations in the structure and function of the brain; and that they may be less responsive to adults to nicotine-replacement therapy.” Besides, “adolescents’ greater impulsivity and risk taking also leads them to discount the potential consequences of tobacco experimentation and use.”

If this is an argument against selling them tobacco, it is also an argument against giving them the vote and allowing them into the military. Furthermore, permanent adolescence in all senses other than that of age seems to be an increasing feature of our society.

Most smokers say they wish they had never taken smoking up, though whether (if they are telling the truth) this is because they derive no pleasure or comfort from it or because they have been made to feel guilty by anti-smoking campaigns is not clear. But it does seem that legal restrictions can have an effect on levels of consumption of psychoactive substances. The easier an addictive substance is to obtain, the fewer and less serious the obstacles to its use, the longer addicts’ addiction to it lasts. You can draw whatever conclusions you like.

Raise the age to vote, smoke, and drink alcohol to the age of 21 with two exceptions - you can participate in all adult activities if you are in the military and you are not allowed to participate in all adult activities if you are still carried on your parents health insurance plan.

I'm a non-smoker long past the age of 21, and I say No, No, a thousand times no. Either 18-year old are adults, with all that adulthood entails -- military service, voting, jury duty, legal responsibility for your actions, and, yes, choosing to enjoy legal products that are not good for you -- or they are not and all of the above should be restricted to 21+. If you are too young to choose whether or not to use tobacco or alcohol, you are too young for the other stuff. Make up your mind, society.

I am sick of all this stuff. Stay the hell out of people's lives. The argument about them being able to serve in the military at the age of 18, one might wonder what they are even fighting for? To maintain an ever-more totalitarian state? And all those people willing to dump on youth and their ability to make their own choices, just think how you will feel if driving is banned for "elderly" people past a certain arbitrary cut-off date (surely New York must be working on something like that, too). What they do to youth, they can do to others, as well, so be careful what kind of control you support.

Long past time to start treating young adults as adults. States should be allowed to lower the drinking age to 18. New York can choose to treat its adults like children, but they shouldn't impose extended adolescence on the rest of the country.

We permit 18 year old youths to vote and but not smoke cigarettes or drink alcohol. Mature enough to vote but not mature enough to smoke or drink? Since young people are now permitted to remain on their parent's health insurance to 26, why not make voting, smoking and drinking legal at 26?

Raise the age to vote, smoke, and drink alcohol to the age of 21 with two exceptions - you can participate in all adult activities if you are in the military and you are not allowed to participate in all adult activities if you are still carried on your parents health insurance plan.

I'm a non-smoker long past the age of 21, and I say No, No, a thousand times no. Either 18-year old are adults, with all that adulthood entails -- military service, voting, jury duty, legal responsibility for your actions, and, yes, choosing to enjoy legal products that are not good for you -- or they are not and all of the above should be restricted to 21+. If you are too young to choose whether or not to use tobacco or alcohol, you are too young for the other stuff. Make up your mind, society.

If drinking, smoking and other vices are to be restricted until age 21, so should voting and signing up for the military. If at 18 a child* is too immature to do one, he/she is too immature to do the other.